Last time Hathaway was on Chelsea, she confessed that she doesn't really like working out. Now, she "really likes" hot yoga. So what changed?

"I'd never really gotten over the workout hump where you're so weak and you hate everything and everything is painful," she admits. "I was literally working out next to a pregnant Jessica Alba, and she could do more push-ups than I could!"

Well, based on sneak previews of Anne in the sexy catsuit, she's no weakling anymore! Hathaway also sticks to a vegetarian diet ... but recently, she's been taking it a little too far.

"Right now I'm like living on kale and dust. The catsuit's unforgiving, man," she told Handler, adding that it takes three people to squeeze her into the costume.

However, Hathaway does allow herself a little fun, like a drink every now and then.

"The character's naughty ... if I was perfectly behaved, I wouldn't be honoring her," Hathaway.